echarts.init(document.getElementById('main')).setOption({
  title: {text: 'Line Chart'},
  tooltip: {},
  toolbox: {
      feature: {
          dataView: {},
          saveAsImage: {
              pixelRatio: 2
          },
          restore: {}
      }
  },
  xAxis: {},
  yAxis: {},
  series: [{
      type: 'line',
      smooth: true,
      data: [[12, 5], [24, 20], [36, 36], [48, 10], [60, 10], [72, 20]]
  }]
});